Financial details weren't disclosed in a news release announcing the purchase, which is expected to close at the end of this month. Spokespeople for the firms couldn't immediately be reached for further comment.

Endeavor's managing partners, Justin Serbinski and Jason Thelen, will join Sun as part of the transaction.

Sun's acquisition of the Endeavor fixed-income team reflects its plans to expand trading into new markets and seek new talent, Mr. Dan said in the release.

Historically, Endeavor has traded in a variety of asset classes, from treasuries to futures to options, according to the release.

Sun, which has an affiliate in London, also trades across multiple asset classes. In February 2011, Sun shuttered its options-trading arm, cutting about 40 employees, or a third of its staff.

Mr. Dan also was formerly CEO of MF Global Holdings Ltd. He was succeeded by Jon Corzine, who was at the helm when the company filed for bankruptcy last October.